Remove mysql-connector-python from recommended MySQL driver

[Taragolis]

At least from middle of 2019 we run tests only with mysqlclient driver, and I can't find what the initial reason to make mysql-connector-python supported driver for MySQL backend.

In additional in SQLAlchemy documentation mysql-connector-python listed (1.4, 2.0) as not tested in their CI with potential unresolved issues.

Personally I found this a yet another nice way to shoot in foot or cast wormhole. Maybe I wrong and we should:

• Started test against mysql-connector-python so we could say that this actually a supported driver
• Change original from text from "We also support" to something like "MySQL backend might also work with"

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[hussein-awala]

+1

But I prefer to have the opinions of other people before merging

[uranusjr]

Not sure about using important here, a simple note seems enough to me. It may also be a good idea to mention that it’s possible to use mysql-connector-python but the combination is not actively maintained by Airflow.

[potiuk]

Yeah. I think we should absolutely not use the word "supported" if we don't test it. What we could use is we can make a reference to "You can also attempt to use other drivers. Please consult the SQL Alchemy documentation "

I think it's a but "unfair" to just remove it but, generally moving people out to the place where they can start searching for solution is the best way how we can say "you can try it on your own - see there for details" - this way we delegate it out to SQLAlchemy to describe it "well-enough".

[potiuk]

Yeah. And note shoudl be good-enough

[Taragolis]

What we could use is we can make a reference to "You can also attempt to use other drivers. Please consult the SQL Alchemy documentation "

Hmm.. we've already have it for MySQL backend

If you want to use other drivers visit the `MySQL Dialect <https://docs.sqlalchemy.org/en/13/dialects/mysql.html>`__  in SQLAlchemy documentation for more information regarding download
and setup of the SqlAlchemy connection.

About note vs important vs some other. We have quite a few notes and warnings in Set up a Database Backend so that the reason why I choose this type of block. I don't have any preferences, and could turn into the note

Some quick info about 3 most popular MySQL's DBAPI2 drivers (non-async).

	Tested in Airflow's CI	Tested in SA's CI	Required build package
mysqlclient	✅	✅	Yes
mysql-connector-python	❌	❌	No (since 8.1)
PyMySQL	❌	✅	No, pure python implementation

[potiuk]

What we could use is we can make a reference to "You can also attempt to use other drivers. Please consult the SQL Alchemy documentation "

Hmm.. we've already have it for MySQL backend

If you want to use other drivers visit the `MySQL Dialect <https://docs.sqlalchemy.org/en/13/dialects/mysql.html>`__  in SQLAlchemy documentation for more information regarding download
and setup of the SqlAlchemy connection.

Cool. Then I am good.

[potiuk]

About note vs important vs some other. We have quite a few notes and warnings in Set up a Database Backend so that the reason why I choose this type of block. I don't have any preferences, and could turn into the note

Both are fine for me.